Introduction by Croakey: The Australian public health community is being urged to step up its climate advocacy, to get active in whatever ways it can, as this week’s report from the Intergovernmental Panel on Climate Change (IPCC) warns of a global catastrophe if action is not urgent and immediate.
The impact of the climate crisis comes on so many fronts and with such inequity: for example, as recent analysis has shown people in Melbourne’s poorest suburbs feel the heat more intensely than those in wealthier areas, largely due to urban heat islands (now becoming “heat continents”) created by badly designed buildings, roads and footpaths.
We must add the critical role of trees also to that mix, says the Doctors for the Environment Australia (DEA), which partnered with the WWF-Australia on a simple but shocking experiment on the streets of Sydney and in the report, Trees: the forgotten heroes of our health.
DEA member Dr Shaun Watson makes the case below.
Shaun Watson writes:
The best time to plant a tree was 20 years ago. The second best time to plant a tree is now. So goes the Chinese proverb quoted in The Overstory, the powerful book about trees by Richard Powers.
There are no healthy people without a healthy planet. A healthy planet is inconceivable without trillions and trillions of trees.
As a species we have deforested vast swathes of this precious blue sphere. Let us start reversing the corrosion now, as our opportunity of 20 years ago is long past.
More specifically, let us take up the challenge to save and grow more trees here in Australia, as the WWF-Australia and Doctors for the Environment Australia (DEA) propose in a compelling and clear report, Trees: the forgotten heroes of our health.
I happen to be writing this personal reflection on trees and health in the kitchen of our Federation semi in Bronte, a beachside suburb of Sydney, where 20 years ago we planted a Camelia sasanqua that now embraces the kitchen’s bank of western facing windows (see feature image).
This small tree has kept us cool through a recent heatwave, without the need for an air conditioner.
Heat is a particular issue in large cities, especially in areas that have few green spaces or trees to absorb a fierce sun.
To highlight the value of trees to our neighbourhoods for the WWF-Australia and DEA report, we carried out a simple experiment. During a recent hot day in Toongabbie, in Sydney’s west, a thermometer was used to measure two parallel streets that are virtually identical — except one is lined with trees.
The exercise showed the surface temperature in the tree-lined street was 29.3 degrees Celsius, while the unshaded street reached 50.1 degrees Celsius – a difference of more than 20 degrees.
The WWF-Australia and DEA report states that research has in fact shown that shaded surfaces may be 11-25°C cooler than the peak temperatures of unshaded surfaces.
Superpower qualities
Reducing exposure to extreme heat is vital to our health. Heat can impact people at a much bigger scale than people realise. In Australia heat kills more people than all the other disasters combined. During heat waves people can suffer heart attacks, strokes, heat exhaustion, and complications with medication.
Trees have other superpower qualities beyond providing essential shade on hot days.
They produce oxygen that we breathe, and help clean our air and water from harmful pollutants. Trees feed us, provide us with medicines, and provide homes for our pollinators that help us grow food.
Trees also help improve our mental health, helping to lower the impacts of stress on our minds and bodies. Our physical health and wellbeing is aided by encouraging walking, cycling and other activities in pleasant green surrounds, while outdoor play with trees helps our children build strength, spatial awareness and confidence.
Intact forests can also help to reduce the risk of disease spread from animals to humans (zoonotic diseases), by reducing contact between wild animals and people. In an age of deforestation and land clearing, up to 70 per cent of emerging infectious diseases worldwide are zoonotic.
Trees provide First Nations peoples a connection to Country, and cultural knowledge of trees is a vital part of how they have lived on Country for millennia.
Trees are a carbon store and have a critical role to play in reducing climate change — the biggest threat to health this century.
Just this week the world’s climate scientists released the UN’s Intergovernmental Panel on Climate Change (IPCC) report which stated very clearly that we have a narrowing window to act fast on reducing our emissions to avoid irrevocable damage to the world which sustains all life.
Low cost, low tech, high impact
Tomorrow I will drive my electric vehicle out to my Blacktown practice, in western Sydney. On a hot summer’s day, the car thermometer rises more than ten degrees in the 30 kilometre drive west from the coast, to where it might be as hot as in Broken Hill.
Surrounding the suburb of Blacktown are brand new black-roofed suburbs with hardly a tree in sight, the frontline of heat health impact.
Imagine instead a swaying green canopy, breathing in CO2 and breathing out oxygen, breathing in nitrogen dioxide and microparticles and breathing out cool, calm and health-giving air.
The health bestowing tree is emblematic of the low cost, low tech, high impact “Health Prescription”, for our patients and our planet.
While it might be low tech, the flowering tree first evolved around 140 million years ago. In complexity and subtlety of structure, in function and connectivity, it easily challenges the MRI scanner or exome analysis, a test that detects genetic disorders.
To my medical colleagues: The next time you see a patient with a disease of Western lifestyle, consider prescribing a walk or cycle along tree-lined paths, a healthy picnic in a leafy park or even the planting and nurturing of a sapling.
Also find ways to advocate on behalf of our many patients, often otherwise underprivileged, who simply don’t have these choices. Every level of government needs to understand that access for all to an environment rich in trees is a health equity issue, increasingly urgent as our climate warms.
In the immediate wake of yet another dire IPCC report, I reflect on climate scientist and Climate Councillor Joelle Gergis’ challenge that this is “Humanity’s Moment”.
This is our one and only opportunity to embrace a healthy future. So, the very best time to grow a tree is now. The very best time to cherish the life and health-giving qualities of trees is also now. We must care for trees, so that they can care for us.
Dr Shaun Watson is a neurologist and a member of Doctors for the Environment Australia
See Croakey’s archive of articles on climate and health
